To determine the soot number of a gas, a defined gas volume is usually drawn through a filter paper so that a soot spot remains on the paper. The blackening of the filter paper in the area of the soot spot depends in particular on the soot content of the gas. A so-called “soot number” is ascertained on the basis of the gray value of the soot spot as a measure of the soot content of the gas.
According to the Verordnung über Kleinfeuerungsanlagen (Erste Bundesimmissionsschutzverordnung vom 13. Februar 1996, Anlage III, Abschnitt: “Anforderungen an die Durchführung der Messung im Betrieb”) [Regulations Governing Small Furnace Installations (First Federal Emission Prevention Regulations of Feb. 13, 1996, Appendix III, Section: “Requirements of Performing the Measurement During Operation”), one possibility of determining the blackening of the soot spot is by comparison with a gray value table. To this end, the filter paper is usually clamped in the intake line of the device and is then removed again after the soot spot has been created. Depending on the relevant specification, it may be necessary to perform several such measurements and to determine an average of the soot numbers determined on the basis of the individual measurements. However, use of such a device is very time-intensive because of the required insertion and removal of the filter paper. In addition, handling is made difficult due to the numerous individual elements because the soot number determining device must be set aside for the comparison of the withdrawn filter paper to the gray value table or it must be held in a nonergonomic manner. Furthermore, the soot number determined after each individual measurement is usually recorded by hand.
Therefore, it would be desirable to provide an inexpensive soot number determining device and a method by which a soot number may be easily determined and further processed.